Develop Reference

Consume only two finger touch

I want to catch ONLY two fingers touch (one finger touch must be NOT consumed).
Unfortunately, I need to consume the "one finger touch" in order to get the "two finger touch" events.
I hope I'm a clear.
Here my code :
#Override
public boolean onTouch(View v, MotionEvent m)
{
boolean consumed = false;
int pointerCount = m.getPointerCount();
int action = m.getActionMasked();
if(pointerCount == 2)
{
switch (action)
{
case MotionEvent.ACTION_DOWN:
case MotionEvent.ACTION_POINTER_DOWN:
consumed = true;
break;
case MotionEvent.ACTION_UP:
// Work
break;
case MotionEvent.ACTION_MOVE:
// Some stuff
break;
default:
break;
}
}
else if (pointerCount == 1 && action == MotionEvent.ACTION_DOWN)
{
// This is needed to get the 2 fingers touch events...
consumed = true;
}
return consumed;
}

I've ran into a similar problem and solved my problem by handling all touches at my top view, and propagating the appropriate actions to the views below. In my example, I had an overlay layer that needed to intercept scale gestures (a recognizer is attached in my constructor), while still propagating single touches to my map view below. I haven't sent the actual touch event to my map view, but I've handled it in my top view and sent the appropriate "panning" action to my view below.
#Override
public boolean onTouchEvent(MotionEvent event) {
if(event.getPointerCount() == 2) {
if(event.getActionMasked() == MotionEvent.ACTION_DOWN){
CameraUpdate update = CameraUpdateFactory.newLatLng(initialCoords);
//attachedMapFragment.getMap().moveCamera(update);
}
scaleGestureDetector.onTouchEvent(event);
}else{
if(attachedMapFragment != null) {
if(event.getActionMasked() == MotionEvent.ACTION_DOWN){
initialCoords = attachedMapFragment.getMap().getCameraPosition().target;
lastTouchX = event.getX();
lastTouchY = event.getY();
}else if(event.getActionMasked() == MotionEvent.ACTION_MOVE){
float deltaX = event.getX() - lastTouchX;
float deltaY = event.getY() - lastTouchY;
lastTouchX = event.getX();
lastTouchY = event.getY();
Projection projection = attachedMapFragment.getMap().getProjection();
Point center = projection.toScreenLocation(attachedMapFragment.getMap().getCameraPosition().target);
Point newCenter = new Point(center.x - (int)deltaX, center.y - (int)deltaY);
LatLng newCoords = projection.fromScreenLocation(newCenter);
CameraUpdate update = CameraUpdateFactory.newLatLng(newCoords);
attachedMapFragment.getMap().moveCamera(update);
}
}
}
return true;
}
This way, I had a scale recognizer on my custom view, while the map was still panning appropriately to single touch. Actually, map view wasn't getting any touches at all, my custom view was "routing" the action as seen above. While not always ideal, this would solve the problem in many cases.

Android Zoom is not respond after some time?

I'm developing an application where I'm applying on touch listener to my layout view. I move the layout over screen but that layout doesn't respond well after 10 to 15 secs. Here is my code:
base = (LinearLayout) findViewById(R.id.load);
base.setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View v, final MotionEvent event) {
int motion = event.getAction();
int numberOfPointers = event.getPointerCount();
if (numberOfPointers < 3) {
switch (motion & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
drag = true;
break;
case MotionEvent.ACTION_POINTER_DOWN: {
drag = false;
if (drawWaveForm != null) {
zoom = true;
}
// initial x1 and x2
BitmapDetector.prevX1 = Math.min(event.getX(0), event.getX(1));
BitmapDetector.prevX2 = Math.max(event.getX(0), event.getX(1));
BitmapDetector.prevY1 = event.getY(0);
BitmapDetector.prevY2 = event.getY(1);
}
break;
case MotionEvent.ACTION_MOVE:
if (drag && event.getActionIndex() == 0) {
// Log.d("detecting","inside the action move");
if (touching == false) {
touching = detector.isWaveformAnchor(event.getX(0), event.getY(0));
} else if (touching == true) {
float diff = event.getY(0) - loadWaveFormManager.getCh1_pos();
if ((loadWaveFormManager.getCh1_pos() + diff) < (StaticValues.screenHeight - 50)) {
int tempCh1_pos = (int) (loadWaveFormManager.getCh1_pos() + diff);
loadWaveFormManager.setCh1_pos(tempCh1_pos);
}
drawWaveForm.update(loadWaveFormManager);
}
}
break;
case MotionEvent.ACTION_UP:
// Log.d("detecting","inside the action up");
drag = false;
touching = false;
zoom = false;
break;
case MotionEvent.ACTION_POINTER_UP:
// here different function
return;
}
});
Does anyone have any idea about this? Please help me on this one.

It is not clear from your code what is your problem and when does it happen. I don't see any TimerTask or AsyncTask reference.
I guess, you're trying to do some expensive operation in UI thread, and this freezes your application. Possible long-running candidate is drawWaveForm.update(loadWaveFormManager)
If this is so, you should preform your computations asynchronously, and only then update UI.
By the way, your code will not compile at all:
public boolean onTouch(View v, final MotionEvent event)
should return true or false, instead you perform return; at the end of this method. That leads to an assumption, that you're providing irrelevant code in your question, but still want to receive a relevant answer.
Provide relevant code piece for further analyze.

Currently you are starting thread on touch event use handler instead
of thread

Android: How to make a CustomListView which is in a Fragment in a SlidingDrawer scroll- and clickable?

I would like to set up following layout with working scroll and click events:
My CustomSlidingDrawer.xml:
<com.project.util.CustomSliderDrawer
android:id="#+id/slidingDrawerHotelList"
android:layout_width="0dp"
android:layout_height="match_parent"
android:allowSingleTap="false"
android:content="#+id/content"
android:handle="#+id/handle"
android:orientation="horizontal" >
<RelativeLayout
android:id="#+id/handle"
android:layout_width="0dp"
android:layout_height="match_parent" >
<RelativeLayout
android:id="#+id/content"
android:layout_width="0dp"
android:layout_height="0dp" >
</RelativeLayout>
</RelativeLayout>
</com.project.util.CustomSliderDrawer>
The width of the elements are set during runtime.
Here I have to mention, that my real content is in the handle of the Drawer, and the content is only a dummy. I'm doing that in this way, because I was not able to hide the handle. Or make it invisible. So, if I want to swipe in I touch the handle (my content) and pull. In the SlidingDrawer, the handle is a placeholder for a fragment which contains a CustomListView.
What now works: I can scroll the SlidingDrawer.
What behavior I would like to gain:
On the SlidingDrawer the MotionEvents are detected in X-Axis direction (Vertical swipe). If a MotionEvent in Y-Axis direction is detected, then the Events shoud go to my CustomListView. Even the onClicks should pass through to the ListView.
What I've tried: I read a lot: here, this page and this one
Then I tried to put all the navigation control in the main activity, what makes really sense in my eyes:
MainActivity:
slidingDrawer.setOnTouchListener(new OnTouchListener() {
int downX, downY;
#Override
public boolean onTouch(View v, MotionEvent event) {
int action = event.getAction();
switch (action) {
case MotionEvent.ACTION_DOWN:
downX = (int) event.getX();
downY = (int) event.getY();
break;
case MotionEvent.ACTION_MOVE:
int deltaX = downX - (int) event.getX();
int deltaY = downY - (int) event.getY();
if (Math.abs(deltaX) > Math.abs(deltaY)) {
Log.i(TAG, "scrollX direction");
isVerticalSwipe = true;
} else {
Log.i(TAG, "scrollY direction");
isVerticalSwipe = false;
}
break;
case MotionEvent.ACTION_UP:
break;
}
return false;
}
});
But when I try here to return "isVerticalSwipe" as local, the SlidingDrawer works not properly anymore. :-(
The 2nd try was to intercept the touch events in the custom sliding drawer:
CustomSlidingDrawer:
#Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN:
Log.i(TAG, "onInterceptTouchEvent ACTION_DOWN");
xDistance = yDistance = 0f;
downX = (int) ev.getX();
downY = (int) ev.getY();
break;
case MotionEvent.ACTION_MOVE:
Log.i(TAG, "onInterceptTouchEvent ACTION_MOVE");
final int curX = (int) ev.getX();
final int curY = (int) ev.getY();
xDistance += Math.abs(curX - downX);
yDistance += Math.abs(curY - downY);
downX = curX;
downY = curY;
if (xDistance > yDistance)
return false;
}
return super.onInterceptTouchEvent(ev);
}
Here happens only the DOWN event and the MOVE event is never reached.
I also made some trys with "dispatchTouchEvent" but I got no success.
I know, that the events will pass through the "layer" of my views - from top to bottom.
So it would be perfect to know, how I can implement the construct from the first link above in my CustomSlidingDrawer (= top view) and when a vertical swipe is detected keep and handle it and if it's a horizontal swipe, then please send it to the CustomListView and perform there the events.
Any help, thoughts, ideas or code snippets are appreciated. :)
Thank you!
[EDIT]
I've made some progress. I get now my events from the SlidingDrawer down to my ListView. I can scroll and click in the list - that works fine. But unfortunately, my SlidingDrawer shows no reaction anymore. These lines are in my custom SlidingDrawer:
#Override
public boolean onInterceptTouchEvent(MotionEvent event) {
gestureDetector = new GestureDetector(new MyGestureDetector());
if (gestureDetector.onTouchEvent(event)) {
return true;
} else if (event.getAction() == MotionEvent.ACTION_UP
|| event.getAction() == MotionEvent.ACTION_CANCEL) {
return false;
} else {
Log.i(TAG, "gestureDetector returned false");
return false;
}
}
class MyGestureDetector extends SimpleOnGestureListener {
#Override
public boolean onDown(MotionEvent e) {
Log.i(TAG, "onDown");
downX = (int) e.getX();
downY = (int) e.getY();
return false;
}
#Override
public boolean onScroll(MotionEvent e1, MotionEvent e2,
float distanceX, float distanceY) {
float deltaX = downX - e2.getX();
float deltaY = downY - e2.getY();
if (Math.abs(deltaX) > Math.abs(deltaY)) {
Log.i(TAG, "scrollX direction");
return true;
} else {
Log.i(TAG, "scrollY direction");
return false;
}
}
}
I don't really understand why it's not working, if there is a swipe in x-direction, then my Drawer should handle the gesture, bc I return true. Instead every event is forwarded to the ListView.
I tried to run "dispatchTouchEvent" before the "onInterceptTouchEvent" but I had no success. Maybe there is a better solution instead of using a SlidingDrawer for moving views by finger?

Okay, after a lot of tears, sweat and blood I finally found a solution which works for me: I don't take a SlidingDrawer anymore and move my layout via changing the LayoutParams.
Over the "dispatchTouchEvent" I get access to my list.
#Override
public boolean dispatchTouchEvent(MotionEvent ev) {
if (mGestureDetector.onTouchEvent(ev)) {
return true;
}
if (ev.getAction() == MotionEvent.ACTION_UP) {
Log.i(TAG, "ACTION_UP");
Log.i(TAG, "getLeft: " + getLeft());
if (getLeft() < 280) {
// run ani to left
} else {
// run ani to right
}
}
return super.dispatchTouchEvent(ev);
}
And in my GestureDetector I handle in the overridden onScroll-function the layout translation. If someone has need for the detector don't hesitate to ask, I'll share.

Correctly detecting a swipe on a GridView placed inside a ViewPager in Android

I have a ViewPager which uses GridViews for pages. I would like the ViewPager to switch pages when I swipe across the screen.
The problem is that swipes are not detected when they are made across the GridView. Outside of the GridView, the swipes work correctly; it seems that the GridView is trapping all touch events without passing it to ViewPager first.
While fiddling with the source code, I did this to a custom class extended from GridView:
#Override
public boolean onTouchEvent(MotionEvent event) {
return pager.onInterceptTouchEvent(event);
}
-- where pager refers to the ViewPager class. With this, ViewPager will correctly detect swipes and move pages accordingly, but it doesn't allow GridView to accept any events, so I can't click on the items.
What I would like to be able to do is correctly detect swipes in ViewPager and item clicks on GridView.

I had trouble with colig's implementation, but I was able to get it to work by subclassing ViewPager and overriding the onInterceptTouchEvent() method. I only checked for swipes in the X direction to allow for vertical scrolling if necessary.
private static final int minSwipeDistance = 30;
private float mTouchX;
#Override
public boolean onInterceptTouchEvent(MotionEvent event) {
boolean response = super.onInterceptTouchEvent(event);
float x = event.getX();
switch (event.getActionMasked()) {
case MotionEvent.ACTION_DOWN:
mTouchX = x;
break;
case MotionEvent.ACTION_MOVE:
float dX = Math.abs(x - mTouchX);
if (dX > minSwipeDistance)
return true;
break;
}
return response;
}

Alix is on the right track. I managed to come up with this simple-looking fix. I'm not entirely sure of how it works, but it does! And for future reference, it works for other kinds of views too -- TableLayout, for example -- not just GridView.
#Override
public boolean onInterceptTouchEvent(MotionEvent event) {
x = event.getX();
y = event.getY();
switch (event.getActionMasked()) {
case MotionEvent.ACTION_DOWN: {
downX = x;
downY = y;
return super.onInterceptTouchEvent(event);
}
case MotionEvent.ACTION_MOVE: {
deltaX = Math.abs(downX - x);
deltaY = Math.abs(downY - y);
return super.onTouchEvent(event);
}
case MotionEvent.ACTION_UP: {
if (deltaX > 4 && deltaY > 4) {
super.onTouchEvent(event);
}
}
}
return super.onInterceptTouchEvent(event);
}

You can override onInterceptTouchEvent for dispatch evenement where you want

Android Gallery Flipping issue

I have a Gallery of views that contain a TextView Label and then a listview below that. It works excellent except that in order to get it to flip from element to element, the user has to touch either above the listview (near the label) and fling or in between gallery objects. Sometimes below the listview works too.But I really want to be able to fling while touching the listview too because it takes up a majority of the screen. How can this be done? What code do you need to see?

I had a similar problem and solved this by overriding the Gallery and implementing the onInterceptTouchEvent to ensure that move events are intercepted by the Gallery, and all other events are handled normally.
Returning true in the onInterceptTouchEvent causes all following touch events in this touch sequence to be sent to this view, false leaves the event for it's children.
TouchSlop is needed as when doing a click there is sometimes a small amount of movement.
Would love to claim this as my own idea, but got the basics of the code from the default Android Launcher code.
public class MyGallery extends Gallery{
private MotionEvent downEvent;
private int touchSlop;
private float lastMotionY;
private float lastMotionX;
public MyGallery(Context context) {
super(context);
initTouchSlop();
}
private void initTouchSlop() {
final ViewConfiguration configuration = ViewConfiguration.get(getContext());
touchSlop = configuration.getScaledTouchSlop();
}
#Override public boolean onInterceptTouchEvent(MotionEvent ev) {
final float x = ev.getX();
final float y = ev.getY();
switch (ev.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_MOVE: {
final int xDiff = (int) Math.abs(x - lastMotionX);
final int yDiff = (int) Math.abs(y - lastMotionY);
// have we moved enough to consider this a scroll
if (xDiff > touchSlop || yDiff > touchSlop) {
// this is the event we want, but we need to resend the Down event as this could have been consumed by a child
Log.d(TAG, "Move event detected: Start intercepting touch events");
if (downEvent != null) this.onTouchEvent(downEvent);
downEvent = null;
return true;
}
return false;
}
case MotionEvent.ACTION_DOWN: {
// need to save the on down event incase this is going to be a scroll
downEvent = MotionEvent.obtain(ev);
lastMotionX = x;
lastMotionY = y;
return false;
}
default: {
// if this is not a down or scroll event then it is not for us
downEvent = null;
return false;
}
}
}

You would want to set the onTouchListener() on the listview, or maybe the entire Linear/Relative layout.
getListView().setOnTouchListener(yourlistener) OR set it on the entire layout. If you post a little code, I could help you further. XML and how you are using in with the Java class would be most helpful.